Adjustable foot mechanism for sash balances



NISM FOR SASH BALANCES May 21, 1957 w. E. GENCY ADJUSTABLE FOOT MECHAFiled July '1, 1955 INVENTOR. 5 WILLIAM E. GENCY' BY M, JAIL ZW hlsATTORNEYS United States Patent C William E. Gency, Old Greenwich, Conn.,assignor to Unique. Balance Inc., New York, N. Y., a corporation ofIllinois Application July 7, 1955, Serial No. 520,442 11 Claims. (Cl.16-197) Thisinvcntion relates to mechanisms by means of which:the/tension of the springs 1 of spiralsash balances may be: adjustedand,more particularly, todevices of such character that may be incorporatedin or adjacent to thefoot mechanism of 'the balancesin order tofacilitatethe aforesaid adjustment. 1

Spiral'sash balances. of the general naturewith which this invention isconcerned are illustrated, for example, in U. S. Patent No. 1,864,745.Various mechanisms haveheretofore been designed to permit of adjustmentof the spring tension in these balances. ously suggested adjustingmechanisms,- however, have beeninadequateto' satisfythe requirements ofthe trade either because of the inherent difiiculty of manipulating themor because'the loca ion of the mechanisms has rendered them inaccessibleafter the balances have been installed. 7

An object of the present invention, accordingly, is to provide amechanism by meansof which the spring tension of spiral sash balances ofthe above character may be readily adjusted after the balance has beeninstalled.

Yet another object of the invention is to provide an adjusting mechanismof the above character which may beinexpensively manufactured andconveniently installed, the. mechanism being such as to permitthemanufacture of a sub-assembly which may be installed on location and.connected'to the spiral balance mechanism, the spring tension of whichis to be controlled;

Theforegoing and other objects are attained'by providing an adjustingmechanism that may, be incorporated in or carried by the structure ofthe footplate; the mechanism being so formed as to permit of adjustmentby the application of a tool-such as a screw'driverthereto fromapositiondirectly beneath'the foot plate. Furthermore, the mechanismutilizes aratchet and pawl connection normally biased into engagingposition by a spring which is released by initial axial movement of thescrew driver prior to the turning movement which effects the desiredtension of the balance spring.

in order that theinvention maybe more readily understood, referencewillnow be made to the accompanying drawings, wherein:

Fig. 1 is an exploded view of an adjusting mechanism constructedinaccordance with the present invention, this view illustrating thevarious partsin axial alignment;

Fig. 2 is a perspective view of. a conventional form of spiral sashbalance and' its foot plate with the adjusting mechanism of the presentinvention incorporated therein;

Fig. 3 is.a view similar to Fig. 2;illustrating the manner in1which the:adjustment of the main spring of the. spiral sash balance may beefiected, the parts in this view being shown in a position in which theywould exist at some point during the adjusting operation;

Fig. 4 is a view in horizontal section taken on the plane indicated bythe line 4-4 and looking in the direction of the arrows; and

These previf Eatented May 21, 1957 ice Fig. Sisa view in verticalsection taken .on the plane indicatedby the. line 55 and looking in thedirection of the arrows.

Referring .tothe'above drawings, a conventional form of spiral sashbalanceis illustratedgenerally at'10, the balance comprising a spiral.vspring 11, the upper'end ofwhich' is formed: with an;eye.12 which isadapted to be secured to the window frame and the lower end of which isformed. with a nut 13 having aslot 14 formed therein; Aspirally formedstrip 15 is received within the. $101.14. and is formed witha. varyingpitch, all in accordance with known practice.

In order that. the: spiral sash balance 10 maybe efie'ctively andconveniently secured to the window-sash, afootplatelS is provided inaccordance with common practice. The-toot plate is formed with a tooth17that iszdriven into the lower edge of the sash and with a suitable.number of: apertures l8 to permit the plate tobe secured to thebottomofthe sash by means of screws,

In accordancewith this invention, the tension of the spring 11: oritsloading may be adjusted efiectively by armechanism comprising a-plate19 that is formed-as an extension, somewhat offset, of the foot plate16. A portion of": the .foot. plate is pressed upwardly into a stop orlocatingdetent 20 to facilitate the location of'the foot plateiupon thebottom of the window sash and to prevent the. securing of the foot plateto the sash in such a positionasto impair the operation of the springadjusting mechanism presently to be. described.

Upon opposite sides of the plate 19, pawl teeth 21- are formed in the.form of'the invention illustrated these teeth extending upwardly andlying generally in planes that are perpendicular to the plane of theplate 19. A central aperture 22 is formed in the plate 19 and isadaptedto receive oppositely spaced curved arms 23. The upperextremities of the arms 23' receive between them the lower end of thespiral member 15, a hinge pin 24 being provided-to secure these elementstogether. The upper extremities of the arms 23 are upset or flanged overto provide inwardly extending fianges 25, these flanges serving to makecaptive a coil spring 26 that is received between the arms 23.

As illustrated in Figs. 1, 2, 3 formed'upon an adjusting plate vided'with a slot'28 to receive the bit of a screw driver such as illustratedin phantom in Fig. 3 in order that the mechanism may be manipulated aswill be presently describedi.

A ratchet plate 29 (illustrated particularly in Fig. 1) is formed-withoppositelydisposed notches or recesses 30 th'at are adapted to receivethe pawls 21 and to prevent rotation'of the plate 29 in one direction(counterclockwise as viewed in Fig. 1). The plate 29 is formed with adiametrically extending bar 31 having a central enlargement 32 againstwhich the spring 26 seats in order that the plate 29 may normally beurged downwardly and retained against theplate 19. As a result of theforegoing structure, spaced, semi-circular slots,33 are formed withinthe'plate 29 and through which the arms 23 extend whentheelements are in'assemble'd'posi tion as illustrated in Figs. 2, 3, 4 and 5.

As illustrated in Fig: l, the parts; are assembled by inserting the"arms 23' through the central aperture 22 of the plate 19; placing "theplate 29in position over the plate 19 andwith the arms23extendinggthrough the slots 33, then inserting the coil spring 26between the arms 23 and peeningor hanging over the extehsionsZS into"the position illustrated-in Figs. 4 and 51 In this fashion, the coilspring 26 is captive and the elements including the foot plate 16 areformed as a sub-assembly. This sub-assembly may either be secureddirectly to the lower extremity of the spiral strip 15 at the time and5, the arms 23 are 27, this plate being pro- 3- the sash balance ismanufactured at the point of installation of the sash balance. All thatis required is that the pin 24 be inserted through the apertures in thearms 23 and the aperture in the bottom of the spiral member 15 and thenthe straight end of the pin riveted over to secure the pin againstaccidental removal. In the assembled position, the lower end of thestrip 15 is pressed against the coil spring 26 which in turn engages thecentral enlargement 32 to maintain the pawl teeth 21 in engagement withthe ratchet plate 29.

Adjustment of the tension of the spring 11 'is'accomplished by insertingthe bit of a screw driver (indicated in phantom at 34) into the slot 28.If the tension of the spring 11 is to be increased, then the screwdriver need only be turned in a counter-clockwise direction as viewedfrom below in Fig. 3. This will cause the plate 29 to be moved in acorresponding direction and the pawl teeth 21 will move the plateupwardly to disengage the teeth from the notches 30 (turning of theplate 27 and 1. Au adjusting mechanism for spiral sash balancescomprising a first plate carried by the foot-plate of a spiral means onsaid adjusting member to enable it to be turned by suitable instrument.

2. A device according to claim 1 wherein the means on ratchet and pawlto release balance. 7

3. A device according to claim 1 wherein the means for maintaining theratchet and pawl relationship is a spring.

4. A device according to claim 3 wherein the ratchet mechanismcomprises. a circular ratchet plate mounted between the first plate andthe spring.

5. A device according to claim 3 wherein the extension is formed oftwoarms and the spring is mounted between the arms. a

6. A device according to claim 5 wherein the arms are or be securedthereto comprising a first plate carried by formed with inwardlyextending flanges overlying the spring to render the same captive.

7. A device according to claim 5 wherein the arms are curved to enclosesaid spring and the second plate is formed with a curved slot throughwhich the arms extend.

8. An adjusting mechanism for spiral sash balances the foot plate of aspiral sash balance said first plate having a central aperture thereinand two pawl teeth thereon, an adjusting plate rotatably mounted belowthefirst plate, a ratchet plate above the first plate having two notchesforming two ratchet teeth adapted to engage said pawl teeth and havingtwo slots therein, a spring above said ratchet plate adapted to engagesaid ratchet plate tain said ratchet plate in engagement with said firstplate, said adjusting plate having two arms thereon which extend throughsaid central aperture and said slots, said arms having means wherebythey may be secured to the lower end of a spiral sash balance, saidadjusting plate having a slot therein to enable it to be turned.

9. An adjusting mechanism for spiral sash balances comprising a firstplate carried by the foot plate of a spiral sash balance said firstplate having a central aperture therein and two upstanding pawl teeththereon, an adjusting plate rotatably mounted below the first plate, acircular ratchet plate above the first plate having two notches formingtwo ratchet teeth adapted to engage said pawl teeth and having twocurved slots defining a diameter bar and a central enlarged portion ofsaid bar, a helical spring above said ratchet plate adapted to engagesaid enlarged portion and thereby maintain said ratchet with said firstplate, said adjusting a slot therein to enable it to be turned.

10. An adjusting mechanism for spiral sash balances comprising a firstplate carried by the foot-plate of a thereby to disengage said ratchetand pawl and the tension of the spiral sash balance.

References Cited in the file of this patent UNITED STATES PATENTS1,926,951 Larson Sept. 12, 1933 2,580,705 Tappen Jan. 1. 1952 2,622,267Permi Dec. 23, 1952 and thereby main- 7

